Skin fastener



Feb. 13, 1945.

P. F. ROSSMANN SKIN FASTENER Filed Dec. 19, 1941 FIG-.4.

FIG-ll.

FIG-5.

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INVENTOR fla TTORNH site Y 2 H .H i m W W M Q A specific object isrtoprovidea simplified skin a fastener thecomponent parts of which arere'-,

Patented Feb. 13, 1 45 Peter'F. ItossinanmSnyder, N. Y., assignor toIrvingRosshWcst range,N.J.

Application December 19, 1941, Serial No. 423,555

7 Claims fastener for temporarily assembling or clamping togetherperforated sheet material, inparticular M metal sheets orplatespreparatory to and tofacilitateariveting operation orother work to becarried out on said material.; i a a i In my co-pendingapplication,Serial No. 384,: 461, filed March 21, 1941,entitledClamping device, Ihavedescribed a device of i this character comprising essentially a bodymember or support having an opening preferably equal to theperforationsin the sheets to beclamped, a clamping element movable relative to saidsupport and having a pair of resilient legs or prongs provided with 3shoulders and biased towards each other, and a spreader arranged infixed relation to said support and projectingthrough said opening. Thespreader is interposed between said prongs to 1 hold the same in spacedapart position against 2 their natural bias with thecombinedcross-sectional areaof saidprongs and spreader-beingsubstantially equal to and filling said opening l in assembled position.Furthermore, suitable spring means are arranged;

interposed between saidispreader and said clamping element to permitofmovemerit of said clamping element between two extreme positions, one:

of said positions causing the ends of said prongs 1 r and saidshouldersto pass. beyond said spreader and to be operated intoengagementwith each other in such a manner astc enablerthe insertion of saidprongs through the alignedperforations ofthe pair of sheetstobe clamped;and the other and a firm lockingof said sheets between said support andsaid shouldersheld in spaced apart position by saidspreader. h i Theobject of thepresent invention islto provide a number of improvedfeatures in a device of the above general character is an-effort tosimdesign andimprove the operation there- 3 pllfy the duced to a minimumand can be easily assembled and disassembled for exchange of broken ordefective components! l a i Another object is to permitof the use of aheavy clamping force substantially without damageto themetal sheet orother material being "clamped or assembled. j a I h u u p (01. 85-5) hepresent invention relates toaclamp orskin r in the hands of an unskilledor untrained opera ato'r. h r u p l The above and further objects andadvantages of the invention will becomefmore apparent from the followingdetailed description taken with reference to the accompanying drawingforming part of this specification and wherein;

Figure 1 is a vertical cross-sectional view of a skin fastenerconstructed in accordancewith the principles of theinvention;

Figure 2 is a cross-sectional View taken online t 2---g2 of Figure 1;

Figure 3 is a partial view of the improved and simplified clampingelement; i

Figure 4 is a perspective: partial View showing the spreader memberembodied in Figure 1;

Figure 5 is a vertical viewrshowing theiastener in the insertingpositionduring the operating l cycle and locking elementfor holding Likereference characters the difierent views of the drawing,

having, in the example shown, the shape of'a cup provided with afiange.lO'fat its open end and having a curved or outwardly vaulted bottompro- {of said positions eausingclamping engagement turn followed byfurther sectionsjM and 14" bent o outwardly at ia slightangle (about 3),while the i i A further object is the provision of a simplified clampingmemberconstructed in such a manner as to enable quick and instantinsertion through the perforations in the sheets to beclamped even videdwith a central opening therein which is element which. is "shownseparately in Figure 3 and according to the improved construction isconstituted by. a-unitary wire memberof semicircular'or segmentalcross-section (seeFigure 2) bent in Urfashion with the flat surfacesfacing each other to form a pair of legs orprongs. The

latter are furthermore shaped in such a manner as to comprise a firstpair ofsubstantially para1- lel sections 12 and 12" adjacent totheirbent end followed by intermediate sections I3 and I3 bentinwardlyatasmallangle (about 15) to the central or symmetry line;Sections l3 and I3 are in lowermost orouter sections I5 and @15'provided withlshoulders orprotuberances l6 and I6 are againsubstantially parallel and urged or biased towards each other in thenormal position as shown in t Figure 3.

Figure dis a perspectiveviewshowing the novel the parts of the deviceidentify like parts in In the drawing,,the numeral l0 indicates the bodymember or jsuppo'rtof my improved fastener in the ineffective or non-useand in the operative positions by a substantially T-shaped spreader(Figure 4) having a cross-piece I1 and a spreader member I8 interposedbetween and being in sliding engagement with the fiat inner faces of theprong portions I5 and I5 as shown in Figure -1. The under-surface of thespreader portion I1 is suitably curved to conform to, the inside of thebottom wall of the cup or bodymember I 0. The clamping member I Iprojects beyond the member I0 and has its upper bent end secured to ahead or cap 20 by the aid of a cross-pin 2| passing through diametricalperforations in the cap and embracing the bent upper portion of thprongs. Pin 2| is held in position by a slit resilient annularshapedlocking element 23 placed in a circumferential groove of the cap toenable easy assembly and disassembly of the device during manufactureand for the quick exchange of broken or defective parts during use; Acoil spring 22surrounding the prongs of member II has its lower endengaging the spreader portion II, the upper end of the spring restingwithin a recess in the under-surface of and engaging the cap 20. Spring22 is designed to provide sufiicient clamping force to firmly lock theshoulders I6 and I6 against the under-surface of sheet B in theoperative position of the fastener as shown in Figure 1 or against theunder-surface of the cup II] in the non-use position of the device. Thevaulted or curved construction of the bottom wall of the cup or bodymember ID enables the employment of a heavy spring to securean adequateclamping or firm locking of the sheets A and B with the fastenerwithoutthe danger of damage to the'sheets or other piece to be clamped orassembled.

WhileI have shown the support or body memher. I 0 in the form of a cupit will be understood thatthe same may take any other suitable shapesuch as a u-shapedmetal strip or angle piece or the like, suchmodifications and variations of the component parts of the device beingreadily obvious to those skilled in the art.

In use, the cap 20 is pressed towards the cup III by compressing thespring 22 preferably with the aid of a suitable tool such as a toggledevice or a plier engaging the upper surface of the cap on the one handand the under-surface of the flange 10' on the other hand. In this(inserting) position the prong sections I5 and I5 have passed beyond thespreader portion I8 and are operated into engagement with each other insuch a manner as to allow of ready insertion of the prongs through theholes in the sheets A and B, as shown in Figure 5 which illustrates theposition at the beginning of the insertion cycle. The shoulders I6 andI6 are designed in such a manner as to provide, when in engagement witheach other, a slip fit in the perforations and, due to the parallelshape of the lower sections of the rongs I5 and I5, it is clearly seenthat the insertion is greatly simplified by providing ready guidance ofthe prongs through the perforations during the inserting operation. Inthis position the spreader. .portion l 8- which substantially conformsto the inner faces of the prong sections I4 and. I4 will be readilypositioned between the latter, resulting in the prongs remainingproperly aligned and preventing lateral movement or canting as .isreadily understood.

yond the lower sheet B to cause the sections I5 and I5 and the shouldersI8 and I6 to become spread apart by moving in an upward directiontowards the body member upon release of the spring 22 so as to result ina firm looking or clamping of the sheets between the shoulders and themember Hi.

In order to remove the fastener, the spring is again compressed bypressing the cap 20 against the cup I0 thereby operating the prongsections I5 and I5" into engagement with each other and enabling awithdrawal of the prongs from the perforations in a manner readilyunderstood-from the above.

It will be evident from the foregoing that the v -are accordingly to beregarded in an illustrative rather than a limiting sense.

At the end of the insertion cycle, that is after I claim:

1. In a clamp for clamping sheets through per forations therethrough, abody member having an outwardly vaulted bearing surface provided with acentral opening and engaging said sheets, a clamping element projectingthrough said opening and having a pair of prongs provided with shouldersand biased towards each other, a spreader in fixed relation to said bodyand interposed between said prongs, and means including springs meansinterposed between said body and said element for causing clampingaction between said shoulders and said body upon movement of saidelement towards said body and compression and subsequent release of saidspring means.

2. In a clamp for clamping sheets through perforations therethrough, abody member having an outwardly vaulted bearing surface provided with acentral opening and engaging said sheets,

a clamping element projecting through said opening, said clampingelement being constituted by a unitary wire member bent in U-fashion toprovide a pair of resilient prongs having shoulders and biased towardseach other, a spreader in fixed relation to said body and interposedbetween said prongs, and means including spring means interposed betweensaid body and said element for causin clamping action between saidshoulders and said bodyupon movement of said element towards said bodyby compression and subsequent release of said spring means.

3. In a clamp for clamping sheets through perforations therethrough, abody member having an outwardly vaulted bearing surface provided with acentral opening substantially equal to the aligned perforations in thesheets to be clamped, said bearing surface engaging said sheets in theclamping position,'a clamping element projecting through said opening,said clamping element being constituted by a unitary wire memberbent inU-fashion to provide a pair of resilient prongs having shoulders andbiased towards each other, a spreader in fixed relation-to said body andinterposed between said prongs, and means including spring meansinterposed between said body and said element for causing clampingaction between said body and said shoulders uponmovement of said elementtowards said body by com pression and subsequent release of said springmeans.

4. In a clamp for clamping sheets through per forations therethrough, abody. member having an outwardlyvaulted bearing surface provided with acentral opening andengaging said sheets,

a clamping element projecting through said opening having a pair ofresilient prongs provided with shoulders at the ends thereof and biasedtowards each other, a spreader conforming to and resting. against theinner surface ofsaid body;

\ said spreader having an extension interposed between said prongs, andmeans including spring means interposed between said spreader and saidbody for causing clamping action between said shoulders and said bodyupon movement of said element towards said body and compression andsubsequent release of said spring means.

i 5. In a clamp for clamping sheets through perforations therethrough, abody member having an outwardly vaulted bearing surface provided with a.central opening and engaging/said sheets, a clamping element projectingthrough said opening having a pair of prongs provided with shoulders andbiased towards each other, a spreader frictionally engaging said bodyand having a portion interposed between said prongs, and

means including spring. means interposed between said spreader and saidclamping element for causing clamping action between said body and saidshoulders held in spaced-apart position by said spreader portion. y g ri 6. In a clamp for clamping sheets through per- Til forationstherethrough, a body member having an outwardly vaulted bearing surfaceprovided with a central opening and engaging said sheets,

a clamping element projecting through saidopen ing, said clampingelement being constituted by a unitary wire member bent inU fashion toprovide a pair of resilient prongs having shoulders and. biased towardseach other, a spreader frictionally engaging said bodyand having aportion interposed between said prongs, and means'ineluding spring meansbetween said spreader and said element for causing clamping actionbetween said body and said shoulders held in spaced-apart position bysaid spreader portion. t

7. In a clamp for clamping sheets through perforations therethrough, abody member having an outwardly vaulted bearing surface provided with acentral opening and engaging said sheets, a clamping element projectingthroughsaid open- 20 ing and having a pair of prongs provided withshoulders at the ends thereof and biased towards each other, a spreaderconforming to and frictionally engaging the inside of said bearingsurface, said spreader having a transverse extension 25 interposedbetween said prongs, and means ineluding spring means interposed betweensaid spreader and said element for causing clamping action between saidbody and said shoulders held in spaced-apart position by said extension.

PETER F. ROSSMANN.

